Diagnosing mechanical failure in fans, pumps and motors can be
a tall order, especially if the applications are located in demanding
environments or hard-to-reach places. Many companies overcome
this problem by introducing a condition-monitoring regime, which
provides an early warning of any impending machine failure that
could result in production downtime.

Of course, before
such a solution can be put in place, the potential for failure
has to be recognised. It was determined that a build-up of solids
in its process plant extraction fans could seriously inhibit
production. Matthew Jessop, their Business Machines Engineer
explains: "In the past, there has been a lot of debate about
whether the vibration caused by a build-up of debris on the fans'
impellers was severe enough to shut the fans down
and clean them."

It was eventually
agreed that a systematic approach to cleaning, based on fan performance
and vibration levels, was required. The responsibility of collecting
fan data fell to a 410 Defender sensor - a self-contained, battery-powered
unit developed specifically to provide condition monitoring for
rotating machinery. Featuring an integrated LCD display for immediate
feedback, the compact unit is extremely accurate and of robust
construction.

Although the data collected from the units was used to monitor
build-up and to set thresholds for initiating clean-up operations,
the real problem, Matthew admits, occurs when lumps of build-up
fly off the impeller. "When the build-up on the impeller
reaches a certain level, small lumps fly off causing additional
imbalances in the motor shafts and greater vibration.

Since debris can accumulate quickly, readings are taken twice
during a shift to monitor fan performance and to establish whether
cleaning is required. Matthew says the 410 Defender's unique
design and ingenious operating system has "helped maintain
an interest" in tackling the vibration problem in these
fans. A sharp tap is all that is needed to turn the Defender
on. The display automatically reverts to sleep mode after one
minute, thereby extending the battery's operating life.

Matthew says
following the installation of the 410 Defender units, corrective
procedures were successfully established and fan vibration levels
reduced: "The 410 Defender units have been installed on
300kW fans, which are particularly prone to impeller build-ups.
The 410s are proving extremely reliable and the stainless steel
construction is ideal
for the process plant environment."
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